We will purify L2C plasma membranes in large batches. We will explore various methods of solubilization and fractionation of the membrane protein and glycoprotein components of these membranes in order to establish preparative procedures. Selected components will be purified in large amounts and used for structureal and functional tests. We are especially interested in the membrane histocompatibility antigens and tumor specific antigens of the L2C leukemia.